Overview of Selection Tools
in the Angus Breed
by Kindra Gordon, field editor, Angus Journal
Tonya Amen, genetic services director for AGI, provided an overview of the selection tools provided by the American Angus Association.
RAPID CITY, S.D. (Dec. 2, 2013) — Livestock performance measurements to assist with genetic selection have evolved greatly over the decades — from average daily gains and weaning weight ratios to expected progeny differences (EPDs) and dollar-value ($Value) selection indexes to the genomic enhanced EPDs and indexes of today. Tonya Amen, genetic services director for Angus Genetics Inc. (AGI), provided a brief history of these selection tools Monday evening, Dec. 2, in Rapid City, S.D. The event, sponsored by Zoetis and Certified Angus Beef LLC (CAB), was a precursor to the three-day Range Beef Cow Symposium that kicks off in Rapid City Dec. 3.
“We’ve come a long way," Amen shared, "but I want to emphasize, we haven’t kicked anything out of our toolbox. For cattle selection, producers are still using much of this information.”
Amen noted that Angus breeders have been particularly relentless in collecting and reporting performance data to improve the breed. The American Angus Association is currently the only breed that calculates and releases new EPDs every week. Its database currently includes:
- 17.3 million pedigrees
- 22 million records
- 62 million EPDs
- 50,000 DNA genotypes — a milestone reached at the end of November 2013.
To share an example that EPDs — and other selection tools — do work, Amen shared data comparing calving ease from the past with data since heifer calving ease EPD information has been made available to producers. The result? Calving difficulty has decreased, meaning fewer calves must be pulled. Amen said this is an indication that EPDs are being utilized and that they do work.
Amen noted that while EPDs focus on outputs, $Values were created to encompass the economic cost and the revenue generated by achieving a certain level of output. While the formulas for the multiple-trait indexes are complicated, their use isn’t, providing cattlemen a simple way to consider multiple traits at once. Amen suggested $Values are fairly easy for producers to use as a selection tool because they are expressed in dollars and cents.
For commercial producers selling calves at weaning, Amen says the weaned calf value index ($W) might be worth focusing on when selecting herd sires because it looks at the economic factors of getting a calf weaned.
The beef value index ($B) looks at postweaning traits. Both feedlot ($F) and grid ($G) values contribute to $B. Amen said if a breeder retains ownership in the feedyard, $B is certainly a useful index for selection. For more detailed descriptions of EPDs and $Values, visit www.angus.org/Performance/Default.aspx.
Today, the newest selection tool available is genomically enhanced EPDs (GE-EPDs). These utilize DNA to provide a higher level of accuracy of an animal’s expected performance.
Amen announced that on Dec. 6, a third recalibration to further increase accuracy of the HD 50K test would be released and would now include 38,989 animals in the database. Additionally, a Heifer Pregnancy EPD is being added to the suite of GE-EPDs. For a description of how genomic information is incorporated into Angus EPDs, visit www.angus.org/AGI/GenomicEnhancedEPDsMay2013.pdf.
Editor's Note: This article was written under contract or by staff of Angus Productions Inc. (API), which claims copyright to this article. It may not be published or redistributed without the express permission of API, publisher of the Angus Journal, Angus Beef Bulletin, Angus e-List and Angus Beef Bulletin EXTRA. To request reprint permission and guidelines, contact Shauna Rose Hermel, editor, at 816-383-5270.
